Tension‐Induced Cavitation in Li‐Metal Stripping
Tension‐Induced Cavitation in Li‐Metal Stripping
复制标题
锂金属剥离中的张力诱导空化
DOI：
10.1002/adma.202209091
复制
发表时间：
2022
影响因子：
29.4
通讯作者：
Xin, Huolin L.
中科院分区：
文献类型：
--
作者：
Wang, Chunyang;Lin, Ruoqian;He, Yubin;Zou, Peichao;Kisslinger, Kim;He, Qi;Li, Ju;Xin, Huolin L.
设计稳定的锂金属和支撑固体结构（SSS）在可充电锂金属电池中至关重要。然而，迄今为止，Li金属的剥离动力学及其对支撑固体（包括固体电解质界面）的机械效应仍然是神秘的。在此，通过在电子显微镜中对固态锂金属电池进行纳米级原位观察，发现了两种不同的空穴介导的锂剥离模式，这两种模式由SSS厚度（t）与锂存款半径（r）之比控制。建立了一个定量的标准，以了解损伤容限的SSS上的锂-金属剥离路径。对于机械不稳定的SSS（t/r< 0.21），剥离通过张力诱导的多位点空化进行，伴随着严重的SSS屈曲和颈缩，最终导致Li“捕获”或“死Li”形成;对于机械稳定的SSS（t/r> 0.21），Li金属通过单一空化从根部经历几乎平面的剥离，显示出可忽略的屈曲。这项工作证明了涂覆在固体电解质内部的电子导电前体膜的存在，然而该前体膜可能会被机械损坏，并且它对于高性能固态锂金属电池的精密锂金属支撑结构的设计具有潜在的重要性。
Designing stable Li metal and supporting solid structures (SSS) is of fundamental importance in rechargeable Li‐metal batteries. Yet, the stripping kinetics of Li metal and its mechanical effect on the supporting solids (including solid electrolyte interface) remain mysterious to date. Here, through nanoscale in situ observations of a solid‐state Li‐metal battery in an electron microscope, two distinct cavitation‐mediated Li stripping modes controlled by the ratio of the SSS thickness (t) to the Li deposit's radius (r) are discovered. A quantitative criterion is established to understand the damage tolerance of SSS on the Li‐metal stripping pathways. For mechanically unstable SSS (t/r< 0.21), the stripping proceeds via tension‐induced multisite cavitation accompanied by severe SSS buckling and necking, ultimately leading to Li “trapping” or “dead Li” formation; for mechanically stable SSS (t/r> 0.21), the Li metal undergoes nearly planar stripping from the root via single cavitation, showing negligible buckling. This work proves the existence of an electronically conductive precursor film coated on the interior of solid electrolytes that however can be mechanically damaged, and it is of potential importance to the design of delicate Li‐metal supporting structures to high‐performance solid‐state Li‐metal batteries.